1. Field of the Invention (Technical Field)
The present invention relates to a method for extracting fulvic acid from complexes of humic substances.
2. Description of Related Art
Note that the following discussion refers to a number of publications by author(s) and year of publication, and that due to recent publication dates certain publications are not to be considered as prior art vis-a-vis the present invention. Discussion of such publications herein is given for more complete background and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
Humic substances, hereinafter also referred to collectively as humic substances material(s), are characterized as high molecular weight heterogeneous organic substances that are the components of soils and sediments. Specifically, they are the compounds of which humus is comprised. They are widespread and generally found in areas where there has been dense prehistoric plant growth. They are understood to play an important role in many geo-chemical reactions and processes including the transport of metal ions, contribution to the cation and anion exchange capacity of peat, soil, and water, the water holding capacity of soil, and the binding of various organic molecules.
Because they play a vital role in soil ecosystems, humic substances are considered to be necessary constituents of soil, both for healthy plant growth and for the nutrition of livestock. The practice of agriculture, however, depletes soils of nutrients. It is generally believed that there is widespread mineral nutrient depletion in farm and range soils. Consequently, humic substances are introduced to agricultural soils as fertilizer.
In recognition that humic substances are superior fertilizers, there is an interest in the direct application of some of these substances to plants, and of feeding these to animals. Also, the vitamin and mineral supplement industry is utilizing these substances to supplement human diets that are believed to be deficient in these substances because of their increasingly diminishing concentrations in produce.
Several components of humic substances are believed to be especially beneficial, humic acid and fulvic acid. These are operationally defined in terms of their solubility. Humic acid is the fraction of humic substances that is not soluble in water under acidic conditions but is soluble in water under alkaline conditions. Fulvic acid comprises the fraction of humic substances that is soluble under all pH conditions.
It is believed that because fulvic acid molecules are of a relatively small size, they are more readily absorbed by plants and can carry trace minerals from plant surfaces into plant tissues. Therefore, fulvic acids may be sprayed onto plants to maximize the productive capacity of plants. Fulvic acid is also believed to be of benefit to humans and may be taken orally in liquid form.
However, the methods currently employed for extracting fulvic acid from the other humic substances result in liquids with high pH containing such compounds as phosphoric acid or sulfuric acid. One method, for example, comprises the addition of phosphoric acid or sulfuric acid to a humic substances material in water. A method is needed to extract fulvic acid in a solution that can be safely consumed by humans and animals and/or sprayed on foliage.